This invention relates generally to manhole cover supports and relates, more particularly, to means by which a manhole cover may be elevated with respect to an underlying support frame to compensate for a rise in the elevation of a roadway such as may occur during a resurfacing of the roadway.
It is known that manhole covers which normally rest upon a frame embedded within a roadway may be raised in relation to the frame by positioning an intermediate support between the frame and the cover. Such an intermediate support is commonly adapted to rest upon the frame in place of the manhole cover and has a surface upon which the manhole cover can be positioned. Examples of such intermediate supports are shown and described in U.S. Pat. Nos. 3,891,337, 4,582,450 and 4,867,601.
It is an object of the present invention to provide a new and improved manhole cover support of the aforedescribed class.
Another object of the present invention is to provide such a support having outer dimensions which can be readily adjusted to secure the support tightly within the manhole frame or loosen the support from the frame for removal.
Still another object of the present invention is to provide such a support which cooperates with a layer of roadway material placed around the support during a resurfacing operation in a manner which enhances the securement of the support within the roadway.
Yet another object of the present invention is to provide such a support which can be secured tightly within the manhole frame by a single nut-rotating operation.
A further object of the present invention is to provide such a support which is uncomplicated in construction and effective in operation.